Stability in magnetically confined plasmas

A tokamak is a device with a toroidal geometry that uses magnetic fields to confine a plasma inside a vacuum chamber, in order to produce thermonuclea r fusion reactions, releasing large amounts of energy, larger than that emp loyed in operating the device. There are two fundamental problems that have prevented us from achieving this goal: (1) the appearance of different ins tabilities that are capable of destroying confinement. and (2) the great en ergy losses resulting from transport to the plasma edge. For several years there has been an enormous effort to study the complex physics behind these two phenomena in order to understand the way they affect the plasma so it is possible to control the unwanted effects. In this Project, different asp ects of the tokamak plasma physics are studied, namely: (a) the transition phenomenom to an improved confinement mode (H mode), (b) the effect impurit ies have on plasma dynamics in the cooler edge region, (c) the processes le ading to a "detached divertor" regime, which makes energy extraction more e fficient, and (d) the burn control of a future nuclear fusion reactor using neural networks. All these are important problems and have to be well unde rstood before the design and construction of a tokamak-based thermonuclear reactor can be undertaken.